FAILING DEGLUTITIVE INHIBITION IN PRIMARY ESOPHAGEAL MOTILITY DISORDERS

Background/Aims: Primary esophageal motility disorders (achalasia, dif fuse esophageal spasm, and intermediate forms) are suggested to be cau sed by different degrees of inhibitory dysfunction; however, direct ev idence for this hypothesis has never been presented in humans. The aim of this study was to measure the degree of inhibition that precedes d eglutitive contractions in patients with primary motility disorders. M ethods: Deglutitive inhibition was examined in patients with primary m otility disorders: 9 with achalasia, 6 with symptomatic diffuse esopha geal spasm, and 5 with intermediate forms. An artificial high-pressure zone was created in the esophageal body by inflating a balloon to a c ritical level, and pressure changes were measured at the interface bet ween the balloon and esophageal wall. Inhibition was visualized as a r elaxation of the artificial high-pressure zone. Results: An inverse re lationship was found between the degree of inhibition and the propagat ion velocity of the deglutitive contraction (r = 0.75; P < 0.001). Nor mally propagated contractions were preceded by an inhibition of 84.2% +/- 3.6%; fast-propagating contractions were preceded by partial inhib ition of 40.6% +/- 6.2%; and, in case of simultaneous contractions, in hibition was absent, i.e., 2.6% +/- 1.6%. Conclusions: The spectrum of primary motility disorders is an expression of a progressively failin g deglutitive inhibition.